Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group
Journal Home About Issues in Progress Current Issue All Issues Feature Issues

Opimization of imprintable nanostructured a-Si solar cells: FDTD study

Christian Fisker and Thomas Garm Pedersen

Open Access Open Access

Abstract

We present a finite-difference time-domain (FDTD) study of an amorphous silicon (a-Si) thin film solar cell, with nano scale patterns on the substrate surface. The patterns, based on the geometry of anisotropically etched silicon gratings, are optimized with respect to the period and anti-reflection (AR) coating thickness for maximal absorption in the range of the solar spectrum. The structure is shown to increase the cell efficiency by 10.2% compared to a similar flat solar cell with an optimized AR coating thickness. An increased back reflection can be obtained with a 50nm zinc oxide layer on the back reflector, which gives an additional efficiency increase, leading to a total of 14.9%. In addition, the patterned cells are shown to be up to 3.8% more efficient than an optimized textured reference cell based on the Asahi U-type glass surface. The effects of variations of the optimized solar cell structure due to the manufacturing process are investigated, and shown to be negligible for variations below ±10%.

© 2013 Optical Society of America

Full Article  |  PDF Article
More Like This
Embedded biomimetic nanostructures for enhanced optical absorption in thin-film solar cells

Min-An Tsai, Hao-Wei Han, Yu-Lin Tsai, Ping-Chen Tseng, Peichen Yu, Hao-Chung Kuo, Chang-Hong Shen, Jia-Min Shieh, and Shiuan-Huei Lin
Opt. Express 19(S4) A757-A762 (2011)

Nanoimprinted backside reflectors for a-Si:H thin-film solar cells: Critical role of absorber front textures

Yao-Chung Tsao, Christian Fisker, and Thomas Garm Pedersen
Opt. Express 22(S3) A651-A662 (2014)

Light trapping in periodically textured amorphous silicon thin film solar cells using realistic interface morphologies

Vladislav Jovanov, Ujwol Palanchoke, Philipp Magnus, Helmut Stiebig, Jürgen Hüpkes, Porponth Sichanugrist, Makoto Konagai, Samuel Wiesendanger, Carsten Rockstuhl, and Dietmar Knipp
Opt. Express 21(S4) A595-A606 (2013)

View More...

Cited By

Optica participates in Crossref's Cited-By Linking service. Citing articles from Optica Publishing Group journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (15)
Fig. 1
Fig. 1 Two different imprinted solar cell structures made from the same anisotropically etched silicon grating.

Download Full Size | PDF

Fig. 2
Fig. 2 Solar cell geometry (a) and incident light polarizations relative to the cell (b).

Download Full Size | PDF

Fig. 3
Fig. 3 Experimentally determined refractive index of a-Si (a). The solar spectrum and absorbed portion in the a-Si with 60nm AR coating and a period of 600nm (b).

Download Full Size | PDF

Fig. 4
Fig. 4 Intentity distribution through the sample for wavelengths (a) λ = 400nm, (b) λ = 500nm, (c) λ = 600nm, and (d) λ = 700nm.

Download Full Size | PDF

Fig. 5
Fig. 5 Integrated quantum efficiency of a-Si solar cells for varying AR coating thicknesses. The black and red curves show the IQE of the structure 1 solar cell with a 600nm period for s- and p-polarization respectively, while the blue and magenta curves are for two flat cells with 500nm and 290nm a-Si layer thicknesses respectively.

Download Full Size | PDF

Fig. 6
Fig. 6 IQE of s-polarized (a) and p-polarized (b) light as a function of lattice period and AR coating thickness for structure 1.

Download Full Size | PDF

Fig. 7
Fig. 7 Same as Fig. 6 but for solar cell structure 2.

Download Full Size | PDF

Fig. 8
Fig. 8 Average IQE of solar cell structure 1 (a) and 2 (b) as a function of lattice period and AR coating thickness.

Download Full Size | PDF

Fig. 9
Fig. 9 Geometry of the cell with initial a-Si layer thickness x = 500nm and variation parameter δ (a). The corresponding IQE as a function of δ (b).

Download Full Size | PDF

Fig. 10
Fig. 10 Geometry of the cell with initial AR coating layer thickness y = 104nm and variation parameter γ (a). The corresponding IQE as a function of γ (b).

Download Full Size | PDF

Fig. 11
Fig. 11 Geometry of three cell grooves with variable widths (a) and the corresponding IQE as a function of the variation parameters w1 and w2 for the s-polarization (b) and p-polarization (c).

Download Full Size | PDF

Fig. 12
Fig. 12 Geometry of the cell with a nc-ZnO layer (left) and IQE as a function of the layer thickness h3 (right).

Download Full Size | PDF

Fig. 13
Fig. 13 Average IQE of the solar cell with a ZnO back reflector layer for structure 1 (a) and 2 (b) as a function of lattice period and AR coating thickness.

Download Full Size | PDF

Fig. 14
Fig. 14 Imprint solar cell model based on an Asahi surface (a) and the Asahi U-type surface profiles used for the modelling (b).

Download Full Size | PDF

Fig. 15
Fig. 15 IQE of the flat and the Asahi U-type textured reference cells with 100nm ZnO in the back reflector layer, compared to structure 1 and 2 cells with optimized lattice periods, for varying AR coating thickness.

Download Full Size | PDF

Equations (1)

Equations on this page are rendered with MathJax. Learn more.

IQE = ∫ λ I sun ( λ ) QE ( λ ) d λ ∫ λ I sun ( λ ) d λ .
Select as filters
Select Topics Cancel
Top
       
© Copyright 2024 | Optica Publishing Group. All rights reserved, including rights for text and data mining and training of artificial technologies or similar technologies.
Privacy | Terms of Use